1. Technical Field
This invention relates to maintaining connections for both mobile and non-mobile nodes in computer networks.
2. Description of the Prior Art
Most mobile devices, such as laptop computers, are frequently shutdown for a variety of reasons. For instance, most are battery-powered, so they often shutdown to conserve battery power. Airlines require such devices to be turned off when taking off or landing regardless of the power source. However, each shutdown causes termination of all applications and a loss of network connectivity, which results in substantial inconvenience to the user.
A problem resulting from the shutdown of a mobile device during an application can be illustrated by an example in which a traveler using a laptop computer in an airport connects to a database server and enters a complex query, which would normally take a long time to execute. However, when the traveler boards the plane, the system must be shutdown prior to takeoff. Upon reaching his destination, the traveler restarts the computer, rebooting the system and restarting the application. Yet, without permanent TCP connections across a system boot, a new connection must be established and the query must be reissued before the reply can be received. Accordingly, prior to the present invention there has been a need for a method by which mobile IP can remain connected across reboots.